Overview
Immunization inequities refer to the avoidable differences in vaccine uptake, leaving certain groups or individuals unvaccinated, undervaccinated or delayed in vaccination. Immunization equity refers to eliminating these avoidable differences in uptake for all population groups.
In the WHO European Region, overall vaccination coverage is high by global standards. However, inequities in coverage persist both between and within countries, often affecting specific geographic areas or population groups. Declines in vaccination coverage and increases in the number of countries with coverage below 90% indicates that the number of people susceptible to VPDs is accumulating over time, creating hidden immunity gaps that increase the risk of outbreaks, even in areas with otherwise well‑performing immunization programmes. Despite progress, inequities remain widespread, as over half of countries (54%) report underimmunized populations at subnational level.
Inequities in immunization are rarely caused by a single factor. They result from a complex interaction between individual behaviours, community norms, health‑system design, policies, service delivery practices and wider social determinants of health. An equity‑oriented immunization programme therefore requires a shift away from one‑size‑fits‑all approaches towards data‑driven, locally tailored solutions.
Immunization equity in the WHO European Region
EIA2030 calls on Member States to strengthen immunization by focusing on equity, life‑course vaccination and local solutions to local challenges. Achieving EIA2030 targets is not possible without addressing inequities.
Key challenges affecting equity across the Region include:
- limited use of disaggregated data, which can obscure pockets of undervaccination at subnational or community levels;
- structural barriers such as inflexible service hours, distance to facilities, vaccine stockouts, legal constraints or administrative requirements;
- competing demands on health systems, particularly during crises, which can disproportionately affect vulnerable groups and widen existing immunity gaps; and
- insufficient integration of equity considerations into routine programme design, monitoring and evaluation.
Recovery of immunization performance following the COVID‑19 pandemic has been slow and uneven across countries. In 2022, only 6% of countries met coverage targets for all key vaccines and the number of countries achieving targets declined compared to pre‑pandemic levels.
Identifying and addressing immunization inequities
Addressing immunization inequities is a continuous, cyclical process rather than a one‑off activity. Between 2020 and 2022, only 38% of countries conducted research and implemented tailored interventions to address undervaccination, and just 21% reported having funded plans targeting high‑risk communities, highlighting gaps in systematic equity‑focused programming.
WHO recommends the following 4‑step equity improvement cycle.
- Identify who and where
Use immunization coverage data, surveillance data and other relevant sources to identify under‑ or unvaccinated populations and geographic areas. National averages should be complemented by subnational and population‑level analysis. - Determine why
Conduct additional research and assessments to identify the root causes of undervaccination, involving relevant target groups at the local level and using behavioural frameworks to help to distinguish between issues of access, convenience, information, system design and trust. - Decide how to respond
Design and implement tailored strategies that address identified barriers. These may include outreach services, adjusted service hours, policy changes, strengthened reminder systems or revised clinical guidance. - Evaluate and adapt
Monitor implementation and impact using clearly defined indicators. Effective interventions should be embedded into routine immunization programmes to ensure sustainability.
Embedding equity into immunization programmes
Equity should be a core principle at every level of immunization programmes – from legislation and policy to service delivery and monitoring.
Key enablers
Critical components for success include:
- a legislative and policy framework that explicitly mandates equitable coverage
- capacity‑building for programme managers and health workers on equity concepts and practices
- collaboration across sectors and with organizations serving disadvantaged groups
- availability and use of high‑quality, disaggregated data
- flexible service delivery models capable of reaching underserved populations
- sustainable financing for tailored interventions.
Without these foundations, immunization programmes risk perpetuating or exacerbating existing inequities.
Why immunization equity matters
Reducing inequities in immunization:
- lowers the risk of VPD outbreaks and severe disease in vulnerable populations;
- protects wider communities by closing immunity gaps;
- strengthens primary health care and trust in health services; and
- contributes to broader social and economic benefits, including improved educational and life outcomes.
Immunization equity is therefore both a public health imperative and a marker of programme success.
WHO response
WHO works with Member States and partners to advance immunization equity by supporting:
- policy development and strategic planning aligned with EIA2030
- guidelines and operational tools to identify, address and monitor inequities
- capacity‑building for national and subnational immunization teams
- data use and analysis, including triangulation of multiple data sources
- advocacy and partnerships to secure political commitment and intersectoral action.
Through these efforts, WHO supports countries to move from high overall coverage to high and equitable coverage, ensuring that no one is left behind.